Electric batteries are commonly used to store and deliver electrical energy. One type of electric battery, known as a lead-acid battery, is commonly employed in vehicles (e.g. cars, trucks, boats, aircraft, and the like) for ignition, lighting, and other related purposes. These applications are typically known as "SLI" or "starting-lighting-ignition" functions. Lead-acid batteries are also increasingly being used in electric vehicle applications in which a battery pack containing multiple batteries provides electric current to power the vehicle.
A conventional lead-acid battery typically includes a number of electrochemical cells housed within a single battery housing. The electrochemical cells within a lead-acid battery are typically electrically connected in a series relationship such that the voltage supplied by the overall battery will be equal to the sum of individual voltages supplied by each electrochemical cell. In a typical application, for example, six two-volt electrochemical cells may be electrically connected within the housing of a single battery such that the battery supplies electrical energy at a voltage of twelve volts.
Each electrochemical cell in a lead-acid battery typically includes electrically-conductive positive and negative current collectors typically manufactured in the form of forarninous (porous) metallic grids. The individual current collectors may be planar (flat) in configuration or spirally-wound as discussed further below. Lead-acid electrochemical cells further include a supply of electrolyte solution therein. This electrolyte solution may be used in different ways within a given electrochemical cell. For example, the electrolyte may be present in liquid form wherein the electrolyte is not contained or absorbed in any structures. This type of battery is normally characterized as a "flooded battery" or "free electrolyte battery." Flooded batteries are generally constructed from planar (flat) positive and negative plates which are arranged in a parallel configuration having the electrolyte solution therebetween.
In contrast, another type of electrochemical cell which is conventionally known as a "retained electrolyte battery" involves a system in which the electrolyte solution is absorbed and retained within a separator element positioned between the plates. Retained electrolyte batteries may involve plate structures which are planar (flat) in configuration and arranged in a parallel orientation having the electrolyte-containing separator member positioned therebetween. Representative electrochemical cells of this type are discussed in the following U.S. Pat. No. 4,421,832 of Uba for ELECTROCHEMICAL CELL and U.S. Pat. No. 5,120,620 of Nelson et al. for BINARY LEAD-TIN ALLOY SUBSTRATE FOR LEAD-ACID ELECTROCHEMICAL CELLS, both of which are hereby specifically incorporated by reference for all that is disclosed therein.
In addition, retained electrolyte batteries may also be produced in a spirally wound configuration in which the positive and negative plates are wound together with the electrolyte-containing separator element positioned therebetween. Examples of this particular battery type are presented in the following U.S. Pat. No. 4,064,725 of Hug et al for APPARATUS FOR MAKING SPIRALLY WOUND ELECTROCHEMICAL CELLS; U.S. Pat. No. 4,212,179 of Juergens for DRIVEN MANDREL AND METHOD; U.S. Pat. No. 4,346,151 of Uba et al. for MULTICELL SEALED RECHARGEABLE BATTERY; U.S. Pat. No. 4,383,011 of McClelland et al. for MULTICELL RECOMBINING LEAD-ACID BATTERY; U.S. Pat. No. 4,606,982 of Nelson et al. for SEALED LEAD-ACID CELL AND METHOD; U.S. Pat. No. 4,637,966 of Uba et al for SEALED LEAD-ACID CELL; U.S. Pat. No. 4,648,177 of Uba et al. for METHOD FOR PRODUCING A SEALED LEAD-ACID CELL; U.S. Pat. No. 4,780,379 of Puester for MULTICELL RECOMBINANT LEAD-ACID BATTERY WITH VIBRATION RESISTANT INTERCELL CONNECTOR; and U.S. Pat. No. 5,091,273 of Hug et al. for METHOD OF APPLYING A TAIL WRAP TO A WOUND ELECTROCHEMICAL CELL AND CELL PRODUCED BY THE METHOD and in U.S. patent application Ser. No. 08/853,377, filed May 8, 1997 of John B. Olson for IMPROVED BATTERY PASTE COMPOSITIONS AND ELECTROCHEMICAL CELLS FOR USE THEREWITH, which are all hereby specifically incorporated by reference for all that is disclosed therein. Spirally wound batteries offer a high degree of efficiency and capacity in a minimal amount of physical space.
Lead-acid batteries may also be produced in two additional types, namely, (1) sealed; and (2) unsealed. In an unsealed battery, the interior of the battery housing is open to the ambient (outside) environment such that fluid communication exists between the interior and the exterior of the battery housing. Thus, in an unsealed battery, hydrogen and oxygen gases, which are produced by all lead-acid batteries during charging, are allowed to escape from the battery housing into the surrounding atmosphere.
Sealed batteries are also known as "recombinant" or "starved electrolyte" batteries. In this type of battery, the battery housing is substantially sealed to prevent the egress of gases therefrom during normal operating situations. In a sealed lead-acid battery, hydrogen and oxygen generated by the battery are retained within the battery housing and allowed to recombine into water molecules. A representative sealed (recombinant) battery system is discussed, for example, in U.S. Pat. No. 4,383,011, previously referenced.
Lead-acid batteries are usually connected to their loads via cables. In the case of a typical automotive SLI battery, for example, the automobile would be provided with a positive and a negative battery cable. The positive cable is then attached to a positive terminal on the battery and the negative cable to a negative terminal on the battery. The connection between a cable and a battery terminal is generally accomplished via a clamping mechanism on the cable which grips a terminal post on the battery. An example of such a clamping mechanism and battery post is illustrated in U.S. Pat. No. 1,779,946 of Nelson for BATTERY CONDITION INDICATOR, which is hereby incorporated by reference for all that is disclosed therein. Alternatively, the connection between a cable and a battery terminal may be accomplished via a threaded member attached to the cable and a threaded receptacle attached to the battery terminal. An example of such a threaded receptacle is disclosed in U.S. Pat. No. 5,283,137 of Ching for COVER ASSEMBLY FOR RECHARGEABLE BATTERY, which is hereby incorporated by reference for all that is disclosed therein.
When removing or installing a battery, the use of such connection mechanisms has proven to be cumbersome and time consuming and further requires the use of tools. In addition, these conventional connection mechanisms often provide less than optimum electrical conductivity, and thus often reduce the potential efficiency of the battery system.
The problems discussed above are amplified in the case of an electric vehicle application where a multiple battery pack is typically used. In such an application, it often becomes necessary to replace a battery in the battery pack. The use of conventional clamping or threaded connectors, as described above, results in time consuming battery replacement and in decreased battery system efficiency.
Various prior attempts have been made to solve the problems discussed above. These attempts have resulted in several "quick connect" designs which allow a battery to be installed without the need for cables. These prior designs, however, suffer from various disadvantages. Most of these designs, for example, require that additional penetrations be made to the battery container. Such additional penetrations are undesirable since each penetration of a battery container represents a potential point of leakage of electrolyte from the container. Many of these prior designs also increase the size of the physical envelope of the battery and/or provide unreliable or inefficient electrical continuity.
Accordingly, it would be desirable to provide a battery system which overcomes the problems described above and, thus, allows for rapid, reliable and efficient battery connections.